<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>DOM与$之间的转换</title>
    <script src="/static/jQuery-1.11/jquery-1.11.3.min.js"></script>
    <script>
        console.log($ === jQuery);
        window.onload = function () {
            //DOM对象
            var btn = document.getElementById('btn');
            console.log(btn);
            //jq对象
            var $btn = $('#btn');
            console.log($btn);
            //DOM对象转换为jq对象
            console.log($(btn));
            //jq对象转换为DOM对象
            console.log($btn.get(0));
        }
    </script>
</head>
<body>
<button id="btn">按钮</button>
</body>
</html>